Fuze for use on rotating artillery ammunition



Jan. 27, 1959 J. L. BROWN, ETAL FUzE: FOR USE oN ROTATING ARTILLERY AMMUNITION Filed oct. 2s. 195s 2 Sheets-Shea?. 1

INVENTOQS duliua L. EIInWl-L Edwin F.' .Shelley 'Tl-Lacuzlcmla Kfzeele JM @Trae/vers Jal 27, 1959 J. L. BROWN, ETAL 2,870,712

/N VEN TOR S Win E alley BY EndnPEK l5f-;IE1E

ATT'OENE YS Juliua L- DUW'I'L FUZE FR USE N ROTATIYG ARTILLERY AMMUNITIUN Julius L. Brown, Mount Vernon, Edwin F. Shelley, New

Rochelle, and Theodore K. Steele, Bayside, N. Y., assignors, by mesne assignments, to the United States of America as represented by the Secretary of the Army Application ctohcr Z3, B53, Serial No. 388,076

16 Claims. (Cl. 102--70.2)

This invention relates to fuses for rotary projectile and more particularly to fuses for the destruction of ammunition to which they are applied.

A primary object of our invention is to provide a simple fuse for projectiles of the point detonating type which as desired prior to firing may be selectively adjusted for a time delay between impact and actuation.

Another object is to provide a more sensitive point detonating fuse that is completely safe to handle and yet reliable in action.

A more specific object is to provide a fuse having an internal structure responsive to target point impact and to target grazing impact.

A still more specific object of our invention is to provide a fuse having a piezoelectric means to electrically actuate a detonator upon point or graze impact.

Other objects will be in part apparent and in part pointed out in the specilication hereafter.

Briefly the invention is carried out by the employment of a piezoelectric crystal which is positioned to be mechanically struck if the projectile engages a target head on and a spring biased ball driven firing pin to explode a detonator upon projectile ogival engagement with a target, such detonation serving to mechanically stress the piezoelectric crystal. The output of the crystal is lead to a detonator which is electrically responsive to explode a preselected booster train to explode the shell. A rotatable disc responsive to firing spin is depended upon to align a portion of the train a predetermined time after the firing cycle.

The invention accordingly comprises the elements and combinations of elements and arrangement of parts hereinafter described, and the scope of the application is indicated in the appended claims.

We have shown a preferred embodiment of our invention in the accompanying drawings in which:

Figure l is a longitudinal section showing the internal arrangement of our invention.

Figure 2 is a cross section through lines 2-2 of Figure l and looking in the direction of the arrows.

Figure 3 is a cross section through lines 3-3 Figure l and looking in the direction of the arrows.

Figure 4 is a cross section through lines 4-4 Figure l and looking in the direction of the arrows.

Figure 5 is a cross section through lines 5--5 Figure l and looking in the direction of the arrows.

Figure 6 is a cross section through lines 6-6 Figure l and looking in the direction of the arrows.

Figure 7 is a cross section through lines 7 7 Figure l and looking in the direction of the arrows.

Figure 8 is a cross section through lines 8 8 Figure l and looking in the direction of the arrows.

Referring now to Figure l there is shown at numeral 1 a tapered fuse body having a windshield 1a, such body being of external ogive form and through which is formed a central axial opening. Starting more or less centrally the kopening has a shoulder 2 defining a reduced diameter portion of the opening forward of such 2,870,712 Patented Jan.- A27, 1959 shoulder. An insulating liner 3 is received in the opening and embraces a metallic hammer receiving cylinder 4 having a boss lll at the rearward end thereof and a fitted elongated cap 5 closing its forward end and threadedly received in portion 6 of the fuse body, substantially as shown. A hammer ball 13 is received within the rearward portion of cylinder 4 which has a part of the end wall thereof cut away to form a ball receiving cup. Immediately forward of the ball 13 is disposed plunger member 14- formed into a point at its forward end and a mushroom head 15 at the rearward end. Detents 16 are mounted in radially disposed bores in body l and are spring urged through suitable openings in cylinder 4 to engage hollowed out portions in the member 14 and thereby releasably retain the member against axial reciprocation. It should be here noted that the plunger and head assembly are fabricated from a metal of a relatively low specific gravity such as an alloy of magnesium and the hammer ball member 13 is made from steel for a purpose that will presently be explained.

A passage 17 is formed in cap 5 to guide plunger member 14 therethrough to engage detonator 18. A spring 19 is disposed between mushroom head 15 and cap 5 and tends to urge the components apart. In` the extreme forward position of the ogive a piezo electric crystal 2.0 is nested between detonator 1S and retainer 2l. The crystal used is barium titanate but it will be understood that any crystalline dielectric which becomes electrically polarized when it is mechanically strained is contemplated in our invention.

To the rear of shoulder 2 is formed an enlarged chamber portion of the central axial opening lined with an insulator 2l such as neoprene. Within a passage in the insulator is a squib 22 having conductors 38 and 35 fastened thereto (see Figures l and 6). A spring clip 7 is suitably secured to the rearward face of shoulder 2 as byscrews 7c and serves to receive .connector 8 which is the terminal of conductor 35. Conductor 38 has termi nal 9 at the end thereof which is received in a bore in end boss il@ as can best be seen in Figure 6.

A turnable plug l2 is rotatably received in a cavity in body l and has axial bores therein to provide a selection of elements to transmit the explosive energy of squib 22. As can best be seen in Figure 8 a time delay element 23 and a superquick open cavity 36 are provided for selection by the gunner prior to tiring.

To the rear of the cavity a rotor 24 is mounted on the longitudinal axis of the fuse body in antifriction bearings 25 and carries a pyrotechnic element 26 adapted to take its aligned position in the explosive train when the rotor is turned to a proper position.

Centrifugally-operated detents 1l as best seen in Figure 4 serve to positively lock the rotor in a safe position and remove during projectile spin to permit arming. A spiral camming groove 23 is cut into the rear face of the rotor to receive and react with ball 29 as will later be explained. A backing plate 3d carries pyrotechnic element 27 to complete the train to booster 3l and has a radial groove 32 cut therein for cooperation with ball 29 under conditions of projectile spin. The fuse body has a portion thereof cut away as at 33 to form a chamber to receive the ball. The aforementioned plate 30 is held against rotation by detent ball 37 seated in a removed segment thereof.

A cup member 34 serves to contain the booster explosive and is threadedly connected to the rear of the fuse body. This cup member also serves to hold ball 37 in place in a manner clear from inspection of Figure l.

The operation of our novel fuse .is as follows: Prior to the tiring either the time delay element 23 o r the Superquick tube 36 is selected by the artilleryman by proper j l gemme rotation of the containing plug 12. Upon ring, the projectile twist gives rise to large contrifugal forces which force detents 11 and 16 outwardly and in acting upon ball 29 creates a component'of force which revolves the r'otor 24 because ofthe spiral, formation of the ball con-y taining caming groove 28. It will be noted that the ball is not free to rotate about Vthe axis of the body but is constrained to remain in the same radial plane with respect thereto by a radial groove 32 cut in xed plate 30. The ball, then, in attempting to reach its extreme radial position under the urging of centrifugal force will revolve the rotor through 90 degrees and come to rest in part at least within the cut away portion 33 of body 1, whereby the rotor is rmly locked in position and pyrotechnic element 26 has been rotated to be aligned with squib 22 and element 27.

Upon point impact with a target the piezoelectric element`20 will be strained and a highvoltage will be generated therein. The path of the electrical energy will be from element 20 through cap 5, cylinder 4, connector 9, lead 38 and to squib 22. The return path is through conductor 35, connector 8, spring leaf 7, and back to the element through body 1. Upon explosion of the squib in response to the passage therethrough of the electrical energy the pressure and heat generated thereby travels backward through the train to set off the main charge. Upon projectile ricochet the rapid change of direction and deceleration produce a component of force acting forward along the axis of the fuze whereby ball hammer 13 is moved violently forward. Because of the relatively large mass of the ball hammer in relation to the mass of the plunger 14 such plunger is moved forward against the urging of spring 19 to explode primer 18. The pressure f lsuch explosion strains the piezoelectrical element 20 and electrical energy is thus generated'to explode the squib 22 in the manner previously explained.

It should be noted that centrifugally responsive detents 16 serve the dual purpose of holding plunger 14 in a safe position and short circuiting the piezoelectric element Z by piercing the insulation 3 and interconnecting the several paths of energy flow, whereby if the element be accidentally struck no energy may be released to iire the squib.

4 of cavities transversely disposed in said plug and selectivelyv alignable at will in response to manual turning of said plug to form a part of the said explosive train, and a time delay pyrotechnic element in one of said cavities.

4. The fuse made according to claim 3 including a spiral groove formed in the said rotor, a ball seated in the said groove whereby the said rotor turns through 90 degrees during projectile spin.

5. In a point detonating fuse for a rotating projectile a body having an axial passage from front to rear, an arming rotor toward the rear of said passage and movable in response to projectile spin, a detonator explodablc upon the passage therethrough of electrical energy and forming a part'of an explosive train, a pyrotechnic element carried by said rotor movable therewith to form a part of said explosive train in armed position, a piezoelectric crystal toward the front of said passage, a primer disposed adjacent said piezoelectric crystal, a plunger in said passage extending toward said primer and normally spaced therefrom, means responsive to projectile ricochet to force said plunger into said primer, an electric circuit including said piezoelectric crystal, plunger, detonator and fuze body, in series in the sequence named, and detent means carried by said fuze body and normally engaging said plunger to short circuit said crystal and immobilize said plunger until said detent means is released by and i in response to projectile spin.

' element in one of said cavities.

f In viewof the above detailed description it will be y seen that the several objects of the invention are achieved and other advantageous results attained.

As Vmany changes could be made in the above constructions without departing from the scopeof the invention it is intended that all matter contained in the above Aspecification or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

We claim:

Y 1. In a point detonating fuse for a rotating projectile a body having an axial passage from front to rear, an arming rotor toward the rear of said passage and movable in response to spin, a detonator explodable upon the passage therethrough of electrical energy and forming a part of an explosive train, a pyrotechnic element carried by said rotor movable to form a part of said explosive train in armed position, piezoelectric means toward the front of said passage, a primer disposed adjacent said piezoelectric means, a plunger in said passage extending toward said primer and normally spaced therefrom, means responsive to projectile ricochet to force said plunger into said primer, a firing circuit including said piezoelectric means, plunger, detonator and fuze body' in series in the sequence named, and centrifugallyreleasable means carried by said fuze body and normally engaging said plunger to immobilize said plunger and short circuit said piezoelectric means until released in response to projectile spin.

2. The fuse according to claim l wherein the said piezoelectric means is a barium titanite crystal.

3. The fuse made according to claim 2 including a turnableplug in said fuse body, there being a plurality 9. The fuse according to claim 8 including a spiral groove formed in the said rotor, a ball seated in the said groove to cam the said rotor through degrees projectile spin.

l0. In a point detonating fuse for a rotating projectile a body having an axial passage from front to rear, an arming rotor toward the rear of said passage and movable in response to spin, a detonator explodable upon the passage therethrough of electrical energy and forming a part of an explosive train, a pyrotechnic element carried by said rotor and movable therewith to form a part of said explosive train in yarmed position, a piezoelectric crystal toward the front of said passage, a primer disposed adjacent said piezoelectric crystal, a plunger of a metal of a relatively low specific gravity in said passage extending toward'said primer and normally spaced therefrom, a ball of a metal of relatively high specific gravity in said passage responsive to projectile ricochet to force said plunger intorsaid primer, an electric circuit including said piezoelectric crystal, plunger, detonator and body in series in the sequence named, and detent means carried by said body and normally engaging said plunger to immobilize the same and to short circuit said piezoelectric crystal until retracted from said plunger in response to projectile spin.

ll. The fuse according to claim 10 including detents normally engaging the said rotor and retractable therefrom in response to projectile spin.

l2. In a point detonating fuze, a fuze body having a longitudinal axis of symmetry and a bore coaxial of said axis, a piezoelectric crystal lixed in the forward end of said bore, a detonator fixed in said bore and operative in response to initiation to exert pressure on said crystal, a ring squib in said body, means connecting said crystal and squib in series circuit, and firing means movable in saidbore to initiate said detonator in response to deceleration.

13. In a point detonating fuze, a fuze body having a longitudinal axis of symmetry and a bore coaxial of said axis, a piezoelectric means fixed in the forward end of said bore, a squib fixed in said body, circuit connections between said piezoelectric means and squib, a detonator mounted in contiguous relation with said piezoelectric means to exert pressure thereon in response to detonation, and means carried by said body and responsive to deceleration thereof to initiate said detonator.

14. A fuze as recited in claim 13, said last-named means comprising a plunger axially reciprocable in said bore, spring means urging said plunger rearwardly of said bore, and an inertia element mounted in said bore rearwardly of said plunger and operable thereon to move the same forwardly into initiating engagement with said detonator in response to deceleration of the fuze.

15. In a point detonating fuze, a fuze body having a longitudinal axis of symmetry and a bore coaxial of said axis, an impact responsive piezoelectric crystal ixed in the forward end of said bore, `an electrically initiated detonator iixed in said bore in position to exert pressure on said crystal in response to initiation, a dielectric liner tting said bore, a metallic cylinder tting said liner, a plunger reciprocable in said cylinder and having a firing means engageable with said detonator in response to forward movement of said plunger within said cylinder, means in said bore rearwardly of said plunger and operable to move said plunger forwardly in response to deceleration of said fuze, a squib within said fuze body and an electric circuit between said crystal and squib and including said crystal cylinder, detonator and fuze body in series in the sequence named.

16. A fuze as recited in claim 15, and a centrifugally actuated detent mounted in a radial passageway in said body, spring means urging said detent radially inwardly through apertures in said liner and cylinder into engagement with said plunger to retain the same in rearward safe position, and simultaneously to short circuit said crystal by contact with said cylinder. v

References Cited in the le of this patent UNITED STATES PATENTS Switzerland Nov. 1, 1951 

